Unreal Development Kit Game Design Cookbook: Over 100 recipes to accelerate the process of learning game design with UDK book and ebook.

UDK has a Download UDK button on the upper tab of their front page. Click this. Also take a look at the UDK News for the current version.

Under Download Latest Release there should be a direct link to the installer file. With GetRight running (or any downloader that supports resumable, large file downloads), right-click on it and choose Copy Link Address. Through the Windows tray choose GetRight's Enter New URL to Download command and paste in the copied link. You should also be prompted for a folder destination for the file, such as your desktop.

Once the installer has downloaded, locate it and run it. During the installation you'll be prompted to agree to Epic Games' license terms, which you should read at least once to answer questions about what you are permitted to do with UDK, and then set a directory to install to. Usually, it makes sense to install to the offered directory. This includes the version number, customarily in the format of the date of release, like UDK-2011-08, which in this book we refer to as ~.

UDK installs its own required utilities including DirectX. If there is a problem with that step (which is rare) you can go to C:\UDK\~\Binaries\Redist\UE3Redist.EXE and run it as administrator. Supposing the dependencies install okay, UDK should then install correctly. Users using Windows XP may face this.

UDK offers to launch itself at the end of the installation, and after that you can find it in the Start | Programs | Unreal Development Kit | Editor shortcut. UDK also adds a desktop shortcut, and you can pin this to the start menu. It is a good idea to edit the UDK shortcut to include a running Log, by right-clicking on it and choosing Properties, then adding -log to the end of the text in the Target: field.

When you uninstall UDK all the user files created can be deleted too, or maintained if you so choose. When you update, this can provide you with a way to access exactly what needs to be transferred over to a new installation.

It is best to keep your content in a few packages all within a single folder (which can then be easily backed up and transferred to other machines too).

Create a subfolder called Yourname in the C:\UDK\~\UDKGame\Content\ folder. In here drop all the model, texture, sound, and animation files you create as you go. To start with you may well have nothing to add, but create the folder anyway for easy access when the time comes.

Flash content is handled differently. This should go in another YournameUI subfolder created in C:\UDK\~\UDKGame\Flash\. This will include any SWF files you import and further subfolders containing content that each SWF uses.

Code is handled separately too. You will need to create a folder called C:\UDK\~\Development\Src\MyGame\Classes\, where MyGame is your folder. You can call it what you like, but all the code in this book assumes you are using MyGame. For a real project you would more likely use the title of the game and create your own naming convention. If you are working with others, consult with the team leader to make sure everyone is on the same page.

When you update UDK and want to carry over settings that you changed in the previous version's config files, you could copy over everything wholesale, but it wouldn't be a safe choice. This is because it is possible that UDK's initial settings may change from version to version. You really just want to take the lines which your game depends on across (the ones that you changed or added yourself). For example, your custom class files are only compiled if they are assigned a path in C:\UDK\~\UDKGame\Config\DefaultEngine.INI, as we'll see later. When you update UDK, you have to tell the new version about your custom classes all over again, and set other default settings for UDK that you want changed too.

Some tutorials refer to maps, the scenes built using UDK, that no longer come with the current installer. For example, the very good Introduction to the Unreal Development Kit DVD by Waylon Brinck, published by The Gnomon Workshop, is based on a map called DM_Sanctuary which is found in the March 2010 release. Later releases don't include it. You would have to download the entire March 2010 release from www.udk.com to obtain the relevant content to follow that DVD (which is well worth it).

Some old releases included a set of material network demonstrations which, after May 2011, seem to have been dropped from the TestPackages folder.

The folder structure for versions after June 2011 has been simplified so that there are now Maps, Mobile, Shared, Showcases, TestPackages, and UT3 folders in the Content Browser. Not all of the original UT3 content is still included.

Older tutorials, those by 3DBuzz for example, sometimes include deprecated tools. One case in particular is the UIScenes editor used to build HUD graphics, whose functionality has been superseded by the incorporation of Autodesk Scaleform tools (through GFxUI nodes in Kismet). Some users didn't like this switch, preferring the old UI building editor, shown below, and their objections still echo through the forums; but on the whole it is generally accepted that the change to GFxUI represents a step forward, though one that takes an effort.

The UIScene editor actually still functions, but is turned off in newer versions in the configuration. Very little is actually preventing it from working. All you have to do is designate in your GameType script (such as MyGame.uc) in the DefaultProperties the line: useclassicHUD=true and it will be enabled after recompiling.

Actorx enables users to export models and animation as assets from 3D applications such as Autodesk 3ds Max, Autodesk XSI and Autodesk Maya. Each supported software has its own plugin folder within the C:\UDK\~\Binaries\actorx\ folder. The plugin or plugins can be copied and pasted to the relevant application.

Additionally, FaceFX , the facial animation tool in UDK, has plugins that work the same way, also including an interface to Autodesk MotionBuilder. To use FaceFX, which is a third party technology, refer to www.facefx.com.

Next, the C:\UDK\~\Binaries\GFx\ folder includes requirements for using SWF [assets] from Adobe Flash in UDK through Scaleform. Information for installing those and using them is covered in Chapter 10, The Way of the Flash UI.

Speed Tree Modeler , a third party foliage generation software is bundled with UDK in a format that only permits assets from it to be compiled for UDK levels. Refer to http://www.speedtree.com/games/ for technical information. It is possible to pick up the functionality of SpeedTree within a few hours. Since it installs with UDK, you can access it from Windows Start | All Programs | Unreal Development Kit | ~ | Tools | Speed Tree Modeller.

Install UDK post June 2011 and start UDK. Go to the File menu and choose New. Choose the Afternoon Lighting template.

The map that opens has a large StaticMesh box for the ground, and a small StaticMesh cube where the Builder Brush is. This StaticMesh is not useful except for scale reference, so select and delete it by pressing Delete. You can't delete the red Builder Brush.

When the Build is finished, which should be fast given the scene simplicity, hit F8 (to Play in Editor (PIE)) or Alt + F8 to play in the active viewport.

Save the map to C:\UDK\~\UDKGame\Content\Yourfolder\Yourfirstmap.UDK.

If you want to you can set any of your maps as one of the map templates that show when UDK loads. To do this we need to save the map to the folder C:\UDK\~\UDKGame\Content\Maps\Templates which is a location specifically for templates. In this case use the extension .UMAP, for instance: YourFirstMap.UMAP.

In the Content Browser, locate the folder or package called Engine.Content.MapTemplateIndex. Add your map here by right-clicking in the Content Browser and choosing New TemplateMapMetadata. When the dialog for this opens, give the Info | Name as YourFirstMap (or whatever you saved your .UMAP file as, without including the ending). Click Okay.

You can add a picture to your newly created TemplateMapMetadata asset. You could take a screen grab and save it as .PNG from Photoshop, and then in the UDK Content Browser right-click and choose Import, and browse to your .PNG. Import the texture to the same package as your TemplateMapMetadata asset.

To complete adding the picture to the template, right-click on the imported texture and choose Copy full name to clipboard. Then find the TemplateMapMetadata asset and double-click it to show its Properties, and in the Thumbnail field of the Template Map Metadata paste the texture name. Save your package and next time you start UDK and choose New Map, yours should appear in the offered templates.

Click on the Preferences menu, and turn on Load Simple Map on Startup. This toggle will prevent or allow skipping through the startup menu to immediately load a set map.

The map which is already loaded (which ought to be a .UMAP as was discussed in the previous recipe) is defined in the configuration file C:\UDK\~\UDKGame\Config\DefaultEditorUDK.ini in the lines at the end:

[UnrealEd.SimpleMap]
SimpleMapName=..\..\Engine\Content\Maps\Templates\Template_MidDay.umap

If you are certain you're developing for mobile you can set Preferences | Always Optimize Content for Mobile which helps to ensure compiled materials and meshes are maintained within platform limitations. View more information at: http://udn.epicgames.com/Three/MigratingMobileJune2011.html. The setting enables ImgTec's PowerVR PVRTC compression when building lighting, which is a lossy, fixed rate texture compression used because mobile devices don't support DXT (DirectX textures). What UDK actually does is cache both DXT and PVRTC compression of the texture and dumps one or the other when cooking the game depending on the destination format (PC or iOS).

Textures for iOS should be larger than 16 x 16 pixels. iOS doesn't support textures that do not have their width-height resolution in powers of two, so what UDK does under the hood is automatically stretch any you use so they'll work. Lightmaps, the scene lighting baked into textures during a build, are often not square so these may need special attention. This command is already set in UDK's configuration in C:\UDK\~\UDKGame\Config\UDKLightmass.INI:

[DevOptions.StaticLighting]
bRepackLightAndShadowMapTextures=True

If you want to alter this state, just add the suffix nopvrtclightmaps to the line in the Target: field of your editor shortcut before launching UDK. If you're just starting out then you won't need to, but it's good to understand how it works.

Moving on, a useful preference to set comes from the fact that clicking on BSP geometry in the perspective view selects the surface under the cursor, not the entire BSP model. In Preferences | Clicking BSP Selects Brush, you can reverse this. Remember, click Ctrl + Shift on a BSP by default selects the entire brush or you can just select it in an orthographic view instead. You can make the BSP brush show shaded faces when selected by going to View | Draw Brush Marker Polys. Try this out, and check the effect of it being on and off.

Some designers like to see a visual guide to what is selected. You can go to Preferences | Highlight Selected with Borders to enable white bounding boxes which face the camera and surround each object in a selection. For better depth perception you can tick Preferences | Enable Wireframe halos so that objects further away get fuzzy edges. Also, you can tick Preferences | Highlight objects under the mouse cursor so as you mouse over objects it identifies one over another in a busy scene. The effect is more obvious in some shading modes (like wireframe or unlit) than others (lit or detail lighting).

If you like to split up your views, you can disable the default Preferences | Resize Top and Bottom Viewports Together. This means that when you drag a view, it is free from the others. By default when you zoom and pan an orthographic view the others follow it. This can also be disabled, through Preferences | Link Orthographic Viewport Movement and will make your viewport response a little more like 3ds Max. A related feature which you may find disconcerting if you use another 3D application is that UDK's default view panning is to move the camera in the direction of the drag (which sends the scene apparently panning away from the drag direction). This can be inverted to a generic style of map panning where the scene stays fixed relative to the cursor during the drag. Preferences | Grab and Drag to Scroll Ortho Cameras sets this.

In versions of UDK from June 2011 on, you can Group actors to make handling them in the view easier. Go to View | Allow Group Selection and tick it. Refer to http://udn.epicgames.com/Three/ActorGrouping.html for further information on grouping. All grouping is controlled by having a selection of objects then right-clicking on them and choosing Group Actors, or Groups if the objects are already grouped.

The four views can be sized by dragging their frames. At the end of the icon row each viewport has, shown below, there is a Tear Off command that creates a floating copy of the view. You can change the layout of the views using the options under the menu View | Viewport Configuration. The default 2 x 2 split is probably easiest to get used to. As with most 3D software, you can shade the views in various modes, using the icons running along the top of each view. Just hold the mouse over the button to get its tooltip, and test each one out to see how it behaves. Each viewport's icon row starts with a letter (P for perspective, T for top, F for front, and S for Side) that you can click to cycle between views.

To navigate the perspective view there are two systems. One way is to use the left mouse to move forward and back, right mouse to look around, and both together to move up and down. This way can be extended by right-clicking and using W A S D for movement, Q and E for up and down, and Z and C for camera zoom. There is an option to use W A S D without holding the right-click under the Preferences menu in the Flight Camera Controls. If you use this you'll have to switch from using W to hide StaticMesh models to using Alt + W.

In the orthographic views you can pan the view using left or right click, zoom using both together or by mouse scrolling. Middle mouse dragging creates a handy ruler that measures units as you draw a red line.

Many of the icons down the side of the editor and along the top of each viewport are just graphics for the same tools or commands in the menu at the top of the editor.

The File menu lets you save and open maps, as well as packages, and import and export terrain content. There is also a list of Recent files which becomes very handy.

The View menu has a lot of functionality including access to the Browsers (Content, Actor Classes, Levels, and so on), actor properties, surface properties and world properties windows, and also the Kismet and Matinee editors. You can enable and adjust the grid scale for viewports and the editor autosave period here, or at the lower right-hand side of the screen through the roll-outs shown here:

The Brush menu, Build menu, and Play menu each provides access to the tools we already mentioned as well as lists their hot keys. The Tools menu offers a few extra utilities, in particular the New Terrain generation window.

With actors in the scene, you can transform them using the Move, Rotate, Scale, and Local Non-Uniform Scaling tools, which can be accessed through icons in the top row or through the Edit menu or by repeatedly pressing Space to cycle them. Non-uniform scale is always in Local space. The hotkey to switch between the World and Local transform modes is the grave key ` or tilde key ~

In one of the UDK updates, a combined transform tool was introduced which can be enabled through the Preferences | Enable Combined Translate/RotateWidget and then cycling the Space bar till it appears. Shown above, this features regular RGB=XYZ axis arrows for movement, a yellow XY movement circle, and a blue arrow to orient an object through a world Z rotation.

In Windows Explorer, within the folder C:/UDK/~/UDKGame/Content/ create a Yourname sub-folder named after yourself or your project. It is highly advisable to put everything you personally create in here, rather than in default folders, because then you can readily transport content from computer to computer or even from one version of UDK to another (assuming you are rolling forward). Since UDK is updated frequently, this can save a lot of noodling around with files. If you work in a team, a folder naming convention may be imposed which you should follow.

Restart UDK. If you then look in the Packages list in the Content Browser you should now see your folder showing there. If you didn't reset, and create a package, you will still be able to save the package into the newly named subfolder but it won't display in the Packages list until you restart. Instead it will display at the bottom of the list, under New Packages in a temporary package called Untitled_1 (and the number will increment if you start a new scene).

A package typically includes some content, and there are two ways to get started. The first is to press the New button at the bottom of the Packages List. This floats a menu for creating content. The other way is to right-click in the gray space of the Content Browser's assets panel and choose New... according to the type of object you want to create.

If you highlight an existing folder in the packages list, such as the one with your name that you created just before, the new object will follow suit and save to that folder. Anyway, you can choose from the floating menu whatever folder you like. You should also give the object a Group and a name. Setting a Group is optional, but really helps a lot. It allows you to organize content that is similar together inside a package. You could put all your meshes in a group called Mesh and all your textures in a group called Texture for example.

Based on the information above, create a New Particle System in your folder, something like this: Yourname.Cascade.DemoPS1 where Yourname is the folder name, Cascade is the group name, and DemoPS1 is the unique asset name. Notice when you create a particle system by using the right-click approach it automatically assigns a Factory preset called Particle System in the creation menu, and after you hit Okay then Cascade opens. Cascade is UDK's particle asset editor. If you use the New icon, you have to set the Factory type yourself from a roll down list, shown above. You should then see a thumbnail in the Content Browser, as shown in the next illustration. Notice the asterisk * next to both the package name and the asset name. This indicates the need to save changes, and is visible in the following screenshot:

If you get a warning saying Cannot Save via the Browser then your new particle system must be in the Untitled_0 package. You should redefine it by pointing it to your own package Yourname in the folder C:\UDK\~\UDKGame\Content\Yourname. To do so, right-click on the asset and choose Move or Rename... and then just enter a specific folder; it would be good to use the folder name you created at the start for your custom assets. If you are starting out with UDK, and have never saved a package of your own already you'll be prompted for a .UPK file save location in Explorer, and should use the folder we've pointed to: C:\UDK\~\UDKGame\Content\Yourname.

You can set as many packages in your folder as you want, or put all your assets in one package. If a single package grows over 300 MB or so, you may hit a performance ceiling for it and get a warning when you save.

If you now delete your folder in Explorer or a .UPK inside of your folder, the Content Browser will no longer include what you deleted next time you run UDK. So, if you save your scene or map, and reload it after deleting content, you will get missing content errors. This is something to be very careful of. Deleting a folder containing a package with an unused, empty particle system won't matter, but deleting a folder with packages full of textures used by model assets in different packages could keep you up fretting long into the night. It is a good idea to periodically copy out and rename backups of your key packages.

If, in the Browser, you want to modify the content which ships with UDK, you shouldn't directly edit it but instead right-click on it and choose Create a Copy... then set the new package name to one of your own, located in your C:\UDK\~\UDKGame\Content\Yourname subfolder, and probably rename the asset too. You can then modify the copy as you wish.

Finally, if you have content from another graphics software you want to import, like a texture or a model, click on the Import button at the bottom of the packages list or right-click in the assets Browser panel and choose Import there. It is the top entry and you may have to scroll up the list to see it.

Download the book's content from the above mentioned URL and extract it into a folder such as C:\Packt\. In the main extracted folder ...\Files\ select the \Development and \UDKGame subfolders and copy or merge them into your UDK installation C:\UDK\~\ where ~ is the version number. These files do not replace any default UDK files, but add additional content referred to in the book. The extra folder ...\Files\Provided Content contains a few additional files such as 3ds Max source scenes. Look for the included archive ImportTest.rar and extract that to a subfolder \ImportTest.

In UDK, in the Content Browser, select YOURFOLDER and choose Import as discussed above. You can import multiple assets at one go. Select the files extracted to C:\UDK\~\UDKGame\Content\Packt\ImportTest and press Open.

When UDK notices the SWF file it will give the following warning:

All the other assets will still come in. As mentioned earlier, SWF file import should be from assets in the C:\UDK\~\UDKGame\Flash\UI\ folder, not from the \UDKGame\Content folder. Don't import the SWF now; instead, move it where it should be, then import it separately. When they are used later in the lessons, each important file's requirements are talked about more.

The rest of the content will go into a package we'll call Packt UDK (just treat it as a throw-away package). While it's possible to do so, it isn't a good idea to press Okay to all if the content is not all of the same type, and here it isn't. There are textures, meshes, and .WAV files. So check that each item you import has the appropriate Group (Mesh, Texture, Mesh, Wav) and press OK for each one. The next few steps detail this.

The included mesh file is an .ASE and was sent out from Autodesk 3DS Max using File | Export Selected with .ASE as the file type. Now you can also use .FBX to transfer between Autodesk modelers and UDK. To import it, it just needs its group name set to Mesh or something to distinguish it from a texture. This goes for the included WAV file, which are sounds, and should have a group named Wavs or Sounds.

The textures mainly import with default settings. Give them the group name Texture. The exception is 256x256_SampleIII_NRM.TGA. The filename ending _NRM is so named to indicate that it contains a normal map. If you are importing Normal map assets which help describe bumpy surfaces in a material in the Import dialog, they require the Compressing Settings: TC_Default setting to be changed to TC_Normalmap. A properly imported normal map will show up pale pink in the Browser. If it shows up dark blue in the Browser, then it has probably been imported without the correct compression settings.

Having imported all the files, your package needs to be saved. Right-click on it and choose Save. The next screenshot shows the imported content, and the Save Package dialog for committing your .UPK file. When prompted for the folder location to save Packt UDK.UPK choose your own folder that you created earlier. Actually this package is not one we'll use directly in the upcoming projects; so deleting it later on and using content from \Yourname\Yourname.UPK and \Packt\Packt.UPK instead will be what's mostly likely to happen.

In the level's View | World Properties | Game Type property set UTGame, if it isn't set already and save to C:\UDK\~\UDKGame\Content\Maps\CookMe.UDK. It is good to have a different folder for final, cookable maps and maps that are still being developed.

Close UDK, then in Windows go to Start | All Programs | Unreal Development Kit | ~ | Tools | Unreal Frontend. Frontend can be used to launch the editor, to launch a game to play, or to package a game. You can also use the search field to pop it up quickly, as shown here:

Once Frontend launches, choose the type of game you are cooking using the preset. Two types are for mobile, and one is for PC. In this case, choose the PC version which is called DM-Deck.

In the Maps to Cook window, highlight the entry DM-Deck and choose Remove. Then click the Add... text button, and choose it from the list (which shows all the valid maps UDK can find in UDKGame\Content). If you haven't got a map to use, the name of any map in the list will do. After all, this is just a test run.

If you intend to bundle together several maps for cooking, you can specify the initial launch map in the field called Launch Map, by turning on Override Default and choosing one from the list, which is based on the maps to cook. Remember, if an included level depends on another (for a menu or go to map upon completion), to avoid errors you will have to include that to cook too.

You can set the Target Directory for the output file (although to be safe, you may as well leave the default setting for this alone).

Along the top of the Frontend interface there are big glossy icons. Click Launch to show the options for it (on mouse release), and click the checkbox to disable this feature. Then, since for now you don't need to compile any scripts, just click on Cook and choose Clean and Full Recook. Then wait till you see the report in the feedback panel showing success.

Now click the icon for Package Game and enable its Step Enabled checkbox, and then click the embedded Package Game command. A dialog will appear asking for a GameLongName and a GameName. GameLongName determines the way your game will appear in Windows in the Start | All Programs menu. The GameName is what's given to the installer filename. Appended to this will be the prefix UDKInstall, so if you typed in MyGame as your GameName, you'd get UDKInstall-MyGame.EXE.

Press Package Game after entering these names, and wait till you get the success notice returned in the messages in Frontend. Once finished you'll have an .EXE installer which installs the same way UDK installs in the folder you specified in the Target Directory field.

With your map loaded press the Emulate Mobile Features icon, the first in the row of icons pictured below. This shows how the game may appear visually.

At the bottom of the Settings window there is a Play button.

The game will cook through a background instance of Frontend then provide a dialog for deployment.

Bear in mind that to actually send an iOS game to hardware you need to be an iOS registered developer. You can register as one from the dialog after pressing Install on iOS device, or do so through Apple's website: http://developer.apple.com/programs/ios/; though because Apple does levy an annual fee for the right to develop on their platforms you want to be ready to do so before you start paying out. Once you are registered you can proceed through the Unreal iOS Configuration dialog to provision and deploy your game. More information on this is available through a link to UDN inside the dialog itself. If you run this by mistake, it is quite okay just to cancel it.

For provisioning, should you be taking things that far, it is recommended on PC to use Safari, given it is Apple's main web platform, as iOS provisioning is generally aimed at Mac computers. Once through the provisioning stage you'll wind up with certification files to import back into the Unreal iOS Configuration wizard, and once those are imported, the last step is to set the bundled content names and display names that will be used by the device for your game's icon.

Once those steps are complete, and you press Ready to Package, your game is sent to the device. This assumes you have gone through the steps starting from the editor, as currently Unreal Frontend itself doesn't complete this stage.

Existing developers of iOS applications who wish to develop iOS games using UDK must export their certificate and private key from the Keychain Access application in order to import it on a PC running UDK.

The Kismet for the scene is contained in a sub-sequence BlockAB. Its functionality is covered in Chapter 4, Got Your Wires Crossed? in the recipe Allowing the player to pick up, carry, and place an object. For now, we just want to get the Breakpoints used to check the Kismet is working.

Right-click on the first event in the sequence and choose Set Breakpoint. Repeat this with all the other events in the sequence. Events are easy to spot, since they have a hexagon shape, and red outlines (that turn yellow when selected).

The next Breakpoint will likely occur after you pick up the rocket launcher and fire a rocket at the platform on the ground. Looking at the Kismet debugger you can see some statistics showing above each involved node, the time it was last activated and the number of times it has activated.

Rather than pressing Play this time, select the event labeled KActor_2 Take Damage, right-click on the icon on its right-hand side called Run to Next Action. Choose Selected and the game will let you play up till the point when the Trigger involved takes damage from the rocket. The statistics above the node will show for the Take Damage event the current level of damage to the involved Trigger. You may see many nodes stepping through as they fire one after the other. This is where you can track the order or correctness of your Kismet sequence.

After this point, pressing Play again from Kismet, you may notice that there is a kind of strange, continual pausing every time you hit Play. This is because one of the events involves a Trigger attached directly to the player, which is triggered by the player continually. So, while the Kismet is showing, look for and select the event Trigger_0 Touch and right-click on it and choose Clear Breakpoint.

Unless you shoot the platform continually, the next Breakpoint to fire will be when you place the carried platform in the space for it against the wall. The event is called Trigger_3 Touch. It's inside the Check Block Int comment box. Directly after that event, the game should pause and show the debugging window again because the platform is removed immediately from the scene by the Destroy action on which we set a Breakpoint earlier.